Although they've increased since last update, the number of confirmed equine West Nile virus (WNV) and Eastern equine encephalitis (EEE) cases has steadied, according to the Animal and Plant Health Inspection Service (APHIS) disease maps.

At the most recent update (Nov. 20), APHIS reported 609 equine WNV cases nationwide and 206 cases of equine EEE since the beginning of the year; both numbers increased from the previous update (Oct. 30), which reported 566 WNV cases and 195 EEE cases. Both current totals far exceed the number of WNV and EEE cases reported nationwide in 2011 (87 and 60, respectively).

As of Nov. 20, Texas had reported the most WNV cases (109), followed by Louisiana (62), Pennsylvania (47), Oklahoma (42), Mississippi (37), Iowa (35), and Indiana (30). Last year, California had the nation's highest WNV total when they reported 15 cases, according to APHIS. The only states in the continental United States that have not reported at least one equine WNV case this year are Delaware, Kansas, Maine, New Hampshire, Vermont, and West Virginia, according to APHIS.

Also as of Nov. 20, Louisiana reported the most equine EEE cases (55), followed by Florida (33), Mississippi (31), and North Carolina (20), according to APHIS. Last year, Wisconsin and New York reported the most cases with 31 and 10, respectively.

Alaska and Hawaii have never reported an equine case of either WNV or EEE.

Another mosquito-borne disease, Western equine encephalitis, has not been identified in the United States this year.